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The effect of the addition of different proportions of silver (Ag) nanoparticles and alcohols in milk scum oil methyl ester on the performance of engine and emission are studied. B20 blend is added with 5% of ethanol, n-butanol, and iso-butanol as ternary additives for the experimental analysis from no load to full load. Furthermore, at a fixed load, operating conditions such as injection pressure (12 and 15 bar) and injection timing (23 degrees and 26 degrees) are varied without and with the addition of 0.8 vol% of Ag (silver) nanoparticles to the fuel blends. Also, the concentrations of Ag nanoparticles are increased from 0.2 to 1 vol% and comparisons are made with diesel and B60 blend. Mathematical models are developed for selected features of engine performance which fits with the experimental values for the purpose of optimization using the Dragon fly algorithm (DA) by considering these models as the objective functions. The concentration of nanoparticles lowers the BSFC significantly and helps in reducing the emission with an increased percentage. Using full biodiesel, 16.6% reduction in BTE was obtained, while use of alcohols prevented this reduction approximately by 5%. A highest of 4.6% improvement was obtained with the addition of Ag nanoparticles. 4.5% reduction in HC and 13% in NOx emission using nanoparticles are obtained. The DA algorithm provided the same optimized value at the end of 30 iterations in different cycles of execution. Nanoparticle addition and use of pressure in the range of 20 bar gives the lowest emission from the engine. Deanship of Scientific Research at King Khalid University, Saudi Arabia through General Research Group Program [R.G.P. 1/104/42] The authors extend their appreciation to the Deanship of Scientific Research at King Khalid University, Saudi Arabia for funding this work through General Research Group Program under Grant No: R.G.P. 1/104/42. WOS:000695088400003 2-s2.0-85114787759

The operating temperature of Li-ion batteries used in modern electric vehicles should be maintained within an allowable range to avoid thermal runaway and degradation. One of the most challenging issues faced by the automobile industry is providing proper thermal management mechanisms to avert thermal runaways. In this work, the effect of operating parameters like volumetric heat generation (Sq), conduction–convection parameter (ζcc), Reynolds number (Re), and Aspect ratio (Ar) on the thermal behavior of a prismatic battery cell is investigated numerically considering a realistic conjugate condition at the battery cell and coolant interface. Air is selected as the coolant that carries the heat generated uniformly in the modern battery cell during charging or discharging from its surface. For variations in Sq from 0.1 to 1.0, ζcc from 0.06 to 0.1, Re from 250 to 2000, and Ar from 10 to 35, the temperature distribution, as well as maximum temperature variation in the battery cell, is determined. Further, the occurrence of the critical threshold of temperature and the necessary change in these operating parameters to avoid thermal runaway is proposed. Finally, the effect of flow Reynolds number and channel spacing on average Pressure and average Nusselt number is also discussed in this study. From the exhaustive analysis on the effect of considered parameters, it is observed that apart from heat generation parameter Sq, other parameters like ζcc and Re play a prominent role in reducing the maximum temperature of the battery cell. However, Ar has a negligible impact on the thermal performance of battery cell irrespective of any value of other parameters considered in this study. It was interesting to find that for Re> 1000, the impact on temperature profiles of the battery cell is minimal, while the other parameters were either kept constant or varying, putting a limit to higher values of Re.

An experimental study on optimum spacing between grooved tubes is reported in this paper. Two grooved tubes having pitch of 10 mm and 15 mm and a plain tube were considered for the heat transfer analysis. The spacing between two tubes with same pitch was varied from 10 mm to 35 mm with a step size of 5 mm. Velocity of air flowing over the tube surfaces was changed from 0.4 m/s to 1 m/s using a blower fan. Based on Nusselt number (Nu) the optimum spacing between the tubes was decided. The optimum spacing between grooved tubes of pitch 10 mm and 15 mm was compared with that of plain tubes. From the experimental analysis it was noticed that with increase in air velocity (increase in Reynolds number) the tube surface temperature reduced irrespective of any tube considered. Nu increased with increase in air velocity for all the tubes. The important conclusion drawn from the present study was that, there exists a limiting spacing (optimum) between the tubes above which no change in Nu was observed. Spacing of 30 mm was found to be the optimum spacing between the tubes irrespective of its surface geometry modifications.

In nuclear power reactors if the maximum temperature (2000ᵒC) of the fuel element like Uranium-dioxide increments and reaches 2865ᵒC then the fuel element melts down leading to heavy loss and damage. To maintain this maximum temperature well below the allowable limit the heat in the fuel element should be conducted and dissipated to the surrounding medium. In this article, the numerical prediction and comparison of thermal performance characteristics of a nuclear fuel element with and without cladding (bare fuel element) having non-uniform energy generation in axial direction is studied in detail. Accordingly, the two-dimensional heat conduction equation having a cosine variation of heat generation term in the axial direction, along with appropriate boundary conditions is solved using second order accurate finite difference schemes. The results are presented for a wide range of parameters like Aspect Ratio Ar , Biot number, Bi , Conductivity ratio, Cr , Thickness ratio, Th , and total heat generation parameter, Qt in the form of transverse temperature profiles and axial temperature profiles. Effect of Cr and Th due to presence of cladding is thoroughly studied. Different range of parameters for which the temperature of the fuel element is within the maximum temperature range is obtained. Critical values of these parameters for which the temperature increments above maximum temperature is also investigated. From the detailed discussion of the results it is concluded that the maximum temperature attained in the fuel element without cladding (bare fuel element) is very much higher than that attained in fuel element with cladding. Also it is observed that for fixed values of Ar , Cr and Th , there exists a critical value of Qt and Bi beyond and below which maximum temperature in the fuel element exceeds its allowable limit.

The prime objective of this investigation is to address the problem of optimum spacing of channels formed by parallel plates having volumetric heat generation, subjected to conjugate forced convection-conduction cooling. Assuming non uniform volumetric heat generation in the plate, the two dimensional equation governing the temperature distribution in the solid domain are solved simultaneously with stream function, vorticity transport, and energy equation for the flow and thermal fields of the fluid domain, using appropriate finite difference method. Keeping aspect ratio ( A r ) of the plate constant, results are presented in the form of effect of conduction-convection parameter ( N c c ), total heat generation parameter ( Q t ), Reynolds number ( R e H ) on the optimum spacing of the plates, for various Prandtl number ( P r ) representing the coolants liquid Sodium, Sodium Potassium, Lead and Helium. It is concluded that the optimum spacing between the plates ( B o p t ) is independent of Q t and N c c , whereas decreases with increase in R e H , and P r . It is also concluded that, Helium acts as the best among all the coolants considered in this study, whereas Lead serves to be the best among all liquid metal coolants.

The term ‘conjugate heat transfer’ refers to a heat transfer process involving an interaction of heat conduction within a solid body with either of the free, forced, and mixed convection from its surface to a fluid flowing over it. It finds application in numerous fields starting from thermal interaction between surrounding air and fins to thermal interaction between flowing fluid and turbine blades. In this article, a systematic literature review of studies pertinent to laminar conjugate conduction-forced convection heat transfer analysis subjected to internal and external flow conditions is performed. The review reports both steady and unsteady state analyses related to experimental, analytical and numerical investigations, in both rectangular and cylindrical geometries with an exemption to micro and mini channel related studies. The studies are categorically put forth initially and an overview of these studies is presented in tabular and graphical form for a swift glance later under each section. This paper is concluded highlighting the salient features of the review, with respect to physical and mathematical models, methodology and applications. The challenges and scope for future study reported at the end of this paper gives the reader an insight into the gaps in the area of conjugate heat transfer analysis of steady and transient state under laminar forced convection flow regimes.

The major goal of this research is to identify optimal arrangement of forced cooling enhancements such as baffles and fins. This research focuses to determine the effect of the different configurations for achieving higher thermal efficiency of the 150 W solar photovoltaic thermal collectors (PV/T). The air-cooling enhancements evaluated in this PV/T system are free duct without fins, ducts with fully transverse fins, partially transverse fins, longitudinal fins with straight baffles and inclined baffles. The experiments are done on hot days of summer in May 2018, India and achieved diverse flow rates of air mass ranging from 0.012 to 0.016 kg/s. The Reynolds number obtained in the flow experiments are in the range of 900–1300 and Nusselt number 35–130.A Computational fluid dynamics study was established to achieve a parametric research to determine surface and outside profiles to study the cooling effectiveness. The impacts on flow rate of air mass on the outlet T, Reynolds Number, coefficient of heat transfer and Nusselt number were studied. The maximum irreversibility occurred at the free type fins whereas minimum irreversibility obtained at longitudinal type with inclined baffles and detected that PV/T system have a prodigious impact on the energy efficacy as well as energy losses increased with increasing surface T. This research displayed that the coefficient of heat transfer of solar panel upsurges by means of growing Reynolds number. Additionally, the PV module thermal efficacy by growing flow rate and reduced with increasing friction factor. An increase by 6–8% in exergy efficiency and 5% to 7% in energy efficiency was recorded while using these forced air-cooling enhancements. A reasonable agreement was reached between experimental and computational model. The exergy performance was increased from 20% to 28 % while using air cooling duct with longitudinal fins and inclined baffles. The thermal energy performance was increased from 12 to 18 % while using air cooling duct with longitudinal fins and inclined baffles. This is the maximum energy efficiency achieved in this PV/T system with the Nusselt number ranging from 30 to 130 and Reynolds number 900–1300. This study showed that Nusselt number of PV/T system upsurges with growing Reynolds number of air flow. The PV module thermal efficacy upsurges by means of growing flow rate as the friction factor increases. The longitudinal fins with inclined baffles provided higher friction factor, thereby ensured higher heat transfer rate. The fins and baffles employed in our research are economical and relaxed to manufacture and install. They bid a fairly lower friction lack in movement of air and henceforth do not necessitate higher fan power. This set up can be used for green and smart cities as it helped to reduce the energy consumption considerably.

In this article, effect of spacing between the battery cells ($$\bar{W}_{\text{f}}$$) on thermal performance of Li-ion battery cells is investigated in detail. Developing a finite volume method-based numerical code for the present analysis, conjugate boundary condition at the cell and coolant interface is considered. SIMPLE algorithm employed for solving the Navier–Stokes equation is validated with famous benchmark lid-driven cavity problem. The heat generation inside the modern battery cell is uniform in accordance with cell zone. Air being the coolant flows between the channel spacing of the battery cells. Forced laminar flow of coolant and steady-state analysis with operating parameters like heat generation term ($$\bar{S}_{\text{q}}$$), Reynolds number (Re), conduction–convection parameter (ζcc), and aspect ratio (Ar) is analyzed with main focus of $$\bar{W}_{\text{f}}$$. The range of $$\bar{W}_{\text{f}}$$ is from 0.02 to 0.14 varied in steps of 0.02 and Re from 250 to 2000 in step of 250. Coupled heat transfer behavior in terms of maximum temperature and average Nusselt number for these parameters is provided. From the numerical analysis, it is observed that for most of the range of operating parameters, at $$\bar{W}_{\text{f}} = 0.02$$, causes a sudden increase in temperature distribution and rise in maximum temperature above critical limits. Average Nusselt number increased with decrease in $$\bar{W}_{\text{f}}$$ up to 0.04 and below this, it dropped. Spacing of $$\bar{W}_{\text{f}} = 0.04$$ and $$\bar{W}_{\text{f}} = 0.06$$ proved to be an optimal spacing at which average Nusselt number is the highest and the maximum temperature is within the safe limit for parameters considered.

The thermal enhancement characteristics of a solar thermal collector (STC) roughened with single arc protrusion ribs are investigated. Out of various techniques used for enhancing the performance of STC, jet impingement and artificial roughness (AR) have a dominant role in heat transfer augmentation. The impinging air jets STC is roughened with single arc protrusion ribs of different parametric values. The combined impact of artificial roughness and jet impingement on the thermo-hydraulic performance of STC is experimentally investigated. Reynolds number is varied from 4000 to 18,000 during experimentation. The AR parameters; relative height ratio of the rib is varied from 0.8 to 1.7, relative pitch ratio of the rib is varied from 9 to12, angle of arc protrusion rib from 40° to 80°, streamwise variation to d hy ratio (hydraulic diameter) is from 0.39 to 0.56 and spanwise variation to d hy ratio from 0.82 to 0.99 during experimentation. The parametric values of artificial roughness for the optimum thermo-hydraulic performance of 1.5, are found out to be relative height ratio of rib = 1.1, relative pitch ratio of rib = 10, angle of arc protrusion rib = 60°, streamwise variation to d hy ratio = 0.43 and Span wise variation to d hy ratio = 0.86. Artificial neural network modeling of Nurs – Nusselt number and f f – friction factor is also performed which accurately predicts these factors easily.

This paper investigates the heat transfer and fluid flow characteristics of liquid metal coolants (such as Sodium, Sodium potassium, Bismuth, Lead, and Lead–bismuth) flowing over a nuclear fuel element having non-uniform internal energy generation numerically using finite difference method. The Full Navier Stokes Equations governing the flow were converted into stream function-Vorticity form and solved simultaneously along with energy equation using central finite difference scheme. For the two dimensional steady state heat conduction and Stream-Function Equation, the discretization was done in the form suitable to solve using ‘Line-by-Line Gauss-Seidel ’ solution technique whereas the discretization of Vorticity transport and energy equations were done using Alternating Direction Implicit (ADI) scheme. After discretization the systems of equations were solved using ‘Thomas Algorithm’. The complete task was done by writing a computer code. The results were obtained in the form of variation of Maximum temperature in the fuel element (hot spots) and its location, mean coolant temperature at the exit .The parameters considered for the study were aspect ratio of fuel element, A r , conduction-convection parameter N cc , total energy generation parameter Q t , and flow Reynolds number Re H . The results obtained can be used to minimize the Maximum temperature in the fuel element (hot spots).

The main objective of this study is to find which Nano fluid is more efficient to transfer heat in a solar flat plate collector by considering various physical parameters like density, specific heat, thermal conductivity, viscosity etc. Model was created and simulated using ‘Ansys-Fluent’ software (K-€ model was used for turbulent flow simulation). Different working fluids such as Al203 and CU0 were made to flow inside the single flat plate collector (SFPC). The simulations were carried out by varying flow rate, volumetric fraction of Nanoparticle etc. to the model to get best power output, efficiency, useful heat and heat losses so that the similar conditions can be applied to the actual system. Moreover attempts were made to increase the output temperature of the fluid to few degrees centigrade.

This paper mainly deals with the mathematical modeling, numerical analysis and Comparison of the thermal performance characteristics of a two-dimensional model of a nuclear fuel element cooled in a surrounding medium with those of one-dimensional model for different cladding materials and cladding thickness. Accordingly, the steady state equations governing the temperature field both for one and two-dimensional models with appropriate boundary conditions are solved numerically using second order central finite difference scheme. Line-by-Line method of solution procedure is then employed to get the algebraic equations which are solved using the famous Thomas Algorithm. Numerically simulated results for a wide range of Biot number, Bi, Conductivity ratio Cr, thickness ratio Th and heat generation parameter, Qt are presented and discussed. It is observed that the one dimensional model prediction is satisfactory only for lower values of parameters considered, for higher values of parameters it over predicts the two dimensional model. It is also observed that for fixed values of Ar, Qt and Bi, there exists a critical value of Th beyond which maximum temperature in the fuel element exceeds its allowable limit.This paper mainly deals with the mathematical modeling, numerical analysis and Comparison of the thermal performance characteristics of a two-dimensional model of a nuclear fuel element cooled in a surrounding medium with those of one-dimensional model for different cladding materials and cladding thickness. Accordingly, the steady state equations governing the temperature field both for one and two-dimensional models with appropriate boundary conditions are solved numerically using second order central finite difference scheme. Line-by-Line method of solution procedure is then employed to get the algebraic equations which are solved using the famous Thomas Algorithm. Numerically simulated results for a wide range of Biot number, Bi, Conductivity ratio Cr, thickness ratio Th and heat generation parameter, Qt are presented and discussed. It is observed that the one dimensional model prediction is satisfactory only for lower values of parameters considered, for higher values of parameters it over predicts t...

Sheet metal segments delivered from press working find wide applications in the territories going from telephonic gadgets to space stations. To design a progressive tool for sheet metal components according to the given details is a testing assignment. This article covers design and modelling of a progressive cam press tool for the component blade fuse holder, which is used in the Printed circuit boards of cars. Few very essential basics of press tools are briefly mentioned. The design and modelling process begins with the careful examination of the component geometry and material specifications. The tool development and modelling of the tool carried out by modelling software Solid Works are provided in detail. Points of interest and detriments of progressive tools over stage tools are additionally spotlighted.